A turbocharger is generally a turbine-driven, forced induction device configured to increase the efficiency and power of an engine. As compared to a naturally aspirated engine, a turbocharged engine produces greater output power because the turbine forces more air, and proportionately more fuel, into the engine's combustion chambers than atmospheric pressure alone. As will be appreciated by those skilled in the art, turbochargers were once referred to as “turbosuperchargers” when all forced induction devices were classified as “superchargers.” At present, however, the term “supercharger” typically is used in reference to only mechanically driven, forced induction devices, such as by way of a belt, gear, shaft, or chain connected to the engine's crankshaft, whereas the term “turbocharger” is used in reference to a turbine driven by the engine's exhaust gas.
Turbochargers find wide use with truck, car, train, aircraft, and construction equipment engines. Turbochargers typically are used with Otto cycle and Diesel cycle internal combustion engines; although more recently, turbochargers have also been found to be useful with automotive fuel cells. One drawback, however, is a lack of specialized or a dedicated line of air filters available for turbochargers and centrifugal superchargers. It will be appreciated that turbochargers and centrifugal superchargers tend to present severe space constraints within engine compartments, thereby limiting the sizes and shapes of potential air filters. Many users rely on short cone-shaped air filters that are designed for other engine applications. Some users resort to making their own screen covers for the turbocharger air inlet.
Those skilled in the art will recognize that the shape of a housing of the turbocharger or supercharger, referred to as a “snail,” presents unique challenges. An inlet receiver of the air filter must be inset into a scroll of the turbocharger or supercharger, thus requiring the user to expose the base of the air filter in order to access and tighten a clamp of the air filter. This encourages the user to apply force to the air filter in an attempt to expose the base, potentially damaging the air filter in the process. Consequently, another drawback is that conventional air filters are not easily installable onto turbochargers and superchargers without potentially damaging the air filters. What is needed, therefore, is an air filter which fits tightly onto air inlets of turbochargers and superchargers without the base of the air filter having to be exposed during installation of the air filter.